| Message ID | 1536573023-6720-2-git-send-email-honghui.zhang@mediatek.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | PCI: mediatek: fixup find_port, enable_msi and add pm, module support | expand |
On Mon, Sep 10, 2018 at 05:50:20PM +0800, honghui.zhang@mediatek.com wrote: > From: Honghui Zhang <honghui.zhang@mediatek.com> > > The Mediatek's host controller has two slots, each with it's own control > registers. The host driver need to identify which slot was connected > in order to access the device's configuration space. There's problem > for current host driver to find out which slot was connected to for > a given EP device. > > Assuming each slot have connect with one EP device as below: > > host bridge > bus 0 --> __________|_______ > | | > | | > slot 0 slot 1 > bus 1 -->| bus 2 --> | > | | > EP 0 EP 1 > > During PCI enumeration, system software will scan all the PCI device > starting from devfn 0. So it will get the proper port for slot0 and > slot1 device when using PCI_SLOT(devfn) for match. But it will get > the wrong slot for EP1: The devfn will be start from 0 when scanning > EP1 behind slot1, it will get port0 since the PCI_SLOT(EP1) is match > for port0's slot value. So the host driver should not using EP's devfn > but the slot's devfn(the slot which EP was connected to) for match. > > This patch fix the mtk_pcie_find_port's logical by using the slot's > devfn for match. > > Signed-off-by: Honghui Zhang <honghui.zhang@mediatek.com> > Acked-by: Ryder Lee <ryder.lee@mediatek.com> > --- > drivers/pci/controller/pcie-mediatek.c | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c > index 861dda6..20b9088 100644 > --- a/drivers/pci/controller/pcie-mediatek.c > +++ b/drivers/pci/controller/pcie-mediatek.c > @@ -337,11 +337,26 @@ static struct mtk_pcie_port *mtk_pcie_find_port(struct pci_bus *bus, > { > struct mtk_pcie *pcie = bus->sysdata; > struct mtk_pcie_port *port; > + struct pci_dev *dev; > + struct pci_bus *pbus; > > - list_for_each_entry(port, &pcie->ports, list) > - if (port->slot == PCI_SLOT(devfn)) > + list_for_each_entry(port, &pcie->ports, list) { > + if (!bus->number && port->slot == PCI_SLOT(devfn)) > return port; > > + if (bus->number) { > + pbus = bus; > + > + while (pbus->number) { > + dev = pbus->self; > + pbus = dev->bus; > + } > + > + if (port->slot == PCI_SLOT(dev->devfn)) > + return port; > + } > + } /* * Walk the bus hierarchy to get the devfn value * of the port in the root bus. */ while (bus && bus->number) { devfn = bus->self->devfn; bus = bus->parent; } list_for_each_entry(port, &pcie->ports, list) { if (port->slot == PCI_SLOT(devfn)) return port; return NULL; Would it work ? Maybe it is a little easier to parse. I think this can even be made easier by using struct device_node* as comparison (and store it in port->slot instead of the port number), I think that the pci_dev representing the port should have the right of_node associated with it by core code, so it is just a matter of finding the first pci_dev parent with an of_node set and compare it against port->slot (that should be converted to a struct device_node*). This ought to be tested and written but I think that's doable. Lorenzo
On Fri, 2018-09-21 at 17:07 +0100, Lorenzo Pieralisi wrote: > On Mon, Sep 10, 2018 at 05:50:20PM +0800, honghui.zhang@mediatek.com wrote: > > From: Honghui Zhang <honghui.zhang@mediatek.com> > > > > The Mediatek's host controller has two slots, each with it's own control > > registers. The host driver need to identify which slot was connected > > in order to access the device's configuration space. There's problem > > for current host driver to find out which slot was connected to for > > a given EP device. > > > > Assuming each slot have connect with one EP device as below: > > > > host bridge > > bus 0 --> __________|_______ > > | | > > | | > > slot 0 slot 1 > > bus 1 -->| bus 2 --> | > > | | > > EP 0 EP 1 > > > > During PCI enumeration, system software will scan all the PCI device > > starting from devfn 0. So it will get the proper port for slot0 and > > slot1 device when using PCI_SLOT(devfn) for match. But it will get > > the wrong slot for EP1: The devfn will be start from 0 when scanning > > EP1 behind slot1, it will get port0 since the PCI_SLOT(EP1) is match > > for port0's slot value. So the host driver should not using EP's devfn > > but the slot's devfn(the slot which EP was connected to) for match. > > > > This patch fix the mtk_pcie_find_port's logical by using the slot's > > devfn for match. > > > > Signed-off-by: Honghui Zhang <honghui.zhang@mediatek.com> > > Acked-by: Ryder Lee <ryder.lee@mediatek.com> > > --- > > drivers/pci/controller/pcie-mediatek.c | 19 +++++++++++++++++-- > > 1 file changed, 17 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c > > index 861dda6..20b9088 100644 > > --- a/drivers/pci/controller/pcie-mediatek.c > > +++ b/drivers/pci/controller/pcie-mediatek.c > > @@ -337,11 +337,26 @@ static struct mtk_pcie_port *mtk_pcie_find_port(struct pci_bus *bus, > > { > > struct mtk_pcie *pcie = bus->sysdata; > > struct mtk_pcie_port *port; > > + struct pci_dev *dev; > > + struct pci_bus *pbus; > > > > - list_for_each_entry(port, &pcie->ports, list) > > - if (port->slot == PCI_SLOT(devfn)) > > + list_for_each_entry(port, &pcie->ports, list) { > > + if (!bus->number && port->slot == PCI_SLOT(devfn)) > > return port; > > > > + if (bus->number) { > > + pbus = bus; > > + > > + while (pbus->number) { > > + dev = pbus->self; > > + pbus = dev->bus; > > + } > > + > > + if (port->slot == PCI_SLOT(dev->devfn)) > > + return port; > > + } > > + } > > /* > * Walk the bus hierarchy to get the devfn value > * of the port in the root bus. > */ > while (bus && bus->number) { > devfn = bus->self->devfn; > bus = bus->parent; > } > > list_for_each_entry(port, &pcie->ports, list) { > if (port->slot == PCI_SLOT(devfn)) > return port; > > return NULL; > > Would it work ? Maybe it is a little easier to parse. > Thanks, this is much better. > I think this can even be made easier by using struct device_node* as > comparison (and store it in port->slot instead of the port number), I > think that the pci_dev representing the port should have the right > of_node associated with it by core code, so it is just a matter of > finding the first pci_dev parent with an of_node set and compare it > against port->slot (that should be converted to a struct device_node*). > > This ought to be tested and written but I think that's doable. > Thanks, I will do my homework and figure a way out through this solution. Currently port->slot is used in too much place to be removed, I guess I need to added a new parameter in the port struct to store the of_node for compare. I'm not sure which way is better, anyway, let me try the new solution. thanks. > Lorenzo
diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c index 861dda6..20b9088 100644 --- a/drivers/pci/controller/pcie-mediatek.c +++ b/drivers/pci/controller/pcie-mediatek.c @@ -337,11 +337,26 @@ static struct mtk_pcie_port *mtk_pcie_find_port(struct pci_bus *bus, { struct mtk_pcie *pcie = bus->sysdata; struct mtk_pcie_port *port; + struct pci_dev *dev; + struct pci_bus *pbus; - list_for_each_entry(port, &pcie->ports, list) - if (port->slot == PCI_SLOT(devfn)) + list_for_each_entry(port, &pcie->ports, list) { + if (!bus->number && port->slot == PCI_SLOT(devfn)) return port; + if (bus->number) { + pbus = bus; + + while (pbus->number) { + dev = pbus->self; + pbus = dev->bus; + } + + if (port->slot == PCI_SLOT(dev->devfn)) + return port; + } + } + return NULL; }